The U.S. government requires that a tax identification number be listed on a W-9 or W-8BEN, for the form(s) to be valid. The following applies to USA citizens.
For form W-9, you must either enter your Company Business tax ID Number (EIN), your U.S. Social Security Number (SSN) or your U.S. Individual Tax ID Number (TIN). Please note that all U.S. tax ID numbers will be verified through the IRS’ E-Services verification system.